Two members of a consanguineous Italian family are described with symptoms of aspartylglycosaminuria. Both patients exhibit mental retardation, some facial dysmorphism and discrete radiological abnormalities affecting the skull and vertebrae. Peripheral blood smears revealed multi-vacuolated lymphocytes. Enzyme studies in leukocytes showed an absence of aspartylglucosaminidase activity. Urine analysis demonstrated abnormal oligosacchariduria. Angiokeratoma corporis diffusum was observed in one patient. The disease is seen as not being limited to Scandinavia or to patients of Scandinavian descent.